Lighting device



May 16, 1939. c. BOL Er AL 2,158,215

- v mmnwme DEVICE Filed March 11, 1956 liil f LMWQQL.

Patented May 16, 1939 UNlTED TATEE QFIQE LIGHTING DEVICE Application March 11, 1936, Serial No. 68,322

in Germany I 4 Claims. Our invention relates to lighting devices using liquid-cooled lamps.

The invention is particularly adapted for use with the liquid-cooled high-pressure gaseous discharge tubes of the type described in the U. S.

patent application Ser. No. 46,952 filed Oct. 26, 1935, to Cornelis Bol, Willem Elenbaas, and Hendricus J. Lemmens, now Patent #2,094,694, and will be described in connection with such tubes. However, the invention is not limited to the. use of such lamps, but can be used with liquid-cooled lamps in general,

In illuminating devices for various purposes and particularly for picture projection, it is very important to replace a defective lamp as quickly as possible to prevent interruptions in the illumination. Although many devices have been proposed to accomplish this when using incandescent lamps, these devices are not suitable for use with liquid-cooled lamps as no means are provided to control the flow of the cooling medium.

The object of our invention is to provide a lighting device using liquid-cooled lamps in which the time dLu'ing which the device is placed out of service due to replacement of a defective lamp is negligible, so that there is practically no interruption in the operation of the device because of this.

In accordance with the invention, we provide a fixed support or head and movably mount one or more lamp housings on this head. The head and the lamp housings are provided with passageways for the cooling medium and with electrical connection for the lamps, whereby when the lamp housing or housings are placed in their operative positions, the electrical and cooling connections are automatically established.

In order that our invention may be clearly understood and readily carried into effect, we shall describe same more fully with reference to the accompanying drawing, in which:

Fig. 1 is a side view of a lighting device according to the invention;

Fig. 2 is a top View of the device shown in Fig. 1;

Fig. 3 is a sectionized view on a slightly en larged scale of a portion of the device taken along line 3-3 of Fig. 2;

Fig. 4 is a side view similar to Fig. 1 but with the lamp housing moved into its inoperative position;

Fig. 5 is a View along line 55 of Fig. 2;

Fig. 6 is a sectionized View of the lamp and holder therefor.

The lighting device shown in Figs. 1 to 6 com- March 20, 1935 (Cl. 2l011.2)

prises a single lamp housing 33 with a lamp 5 (see Fig. 6). The device comprises a fixed head ll provided with a central passageway 63 having a port ti (see Fig. 3) and connected at 40 to a supply of cooling medium.

As shown in Fig. 6, the lamp 5 is secured in a suitable holder so that it can be inserted in the housing 33. More particularly, the ends of the lamp are secured to a cup-shaped metal member 54 and a member I03 of insulating material, by a suitable insulating material l02, which insulates the terminals of the lamp from the cooling liquid. The two terminals of the lamp are connected to pins 31 secured in member I03, which member is provided with two parallel ribs 48.

The lamp 5 is of the type described in the above-mentioned patent and has a high-pressure gaseous filling and a contracted discharge path. Such lamps have a vapor pressure exceeding 6 atmospheres, are artificially cooled, and comprise one or more fixed electrodes which protrude only slightly from a vaporizable supply of mercury or amalgam by which they are partly surrounded. Lamps of this type are capable of producing an intrinsic brilliancy of more than 4,000 international candle power per sq. cm. and are particularly adapted for high intensity illumination. Particularly adapted in this respect are the highpressure mercury vapor discharge tubes whose discharge paths have an intrinsic brilliancy of more than 100,000 international candle power per sq. cm.

Rotatably mounted on the fixed head M is a member 36 having a passageway 62, which in the operative position of the lamp housing, registers with the port El.

Connected to housing 33 is an inlet tube 34 and an outlet tube 35; the tube 34 being connected by means or" a flexible tube 42 to the passageway 62 of the rotatable member 33, and the tube 35 being connected to a tube 43 leading to a drain. The tubes 3t and 35 also serve to support the housing 33 from the member 33 and for this purpose are secured by means of a clamp 31, spring 39 and screw 33 so as to be movable in an axial direction.

As shown in Figs. 1 and 2, the device is in its operative position and the light passes through a condenser lens 29, whereas passageway 62 is connected through port iii to the passageway 60. Thus the cooling medium passes from the passageway (it through port 6!, passageway 62, flexible tube 42, tube St to the lamp housing 33, and after passing around the lamp, leaves through the tube 35 and flexible tube 44.

For making the electric connections to the lamp, a contact device 65 is fixedly supported from the fixed head 4| by means of an arm 45. The contact device 65 is provided with two straight grooves 66 which cooperate with the two ribs 48 on member I03-(see Fig. 4) to ensure proper aligning of the contact pins 3| with spring contacts 32 of device 55 (see Fig. 5) and also to lock the device in the operative position. One of the contacts of the contact device 55 is connected through a lead 86 to one side of a voltage supply (not sho'wn) whereas the other contact is connected to a grounded terminal 41 which also serves to ground the device. Thus in the position shown in Figs. 1 and 2 the lamp is electrically connected and the cooling medium is allowed to circulate through the lamp housing.

To replace the lamp, the housing 33 is moved in the direction of the arrow A by sliding the tubes 34 and 35 through the spring clamp whereby the ribs .8 slide through grooves 66, and pins 3|, which are connected to the terminals of the lamp, break contact with spring contacts 32 (Fig. 5) to thereby automatically interrupt the electrical connections to the lamp. With the lamp housing withdrawn, the member 36 together with thehousing are rotated counterclockwise whereby the device assumes the position shown in Fig. 4, In this position, passageway 52 is disconnected from the passageway 69 and flow of cooling fluid is interrupted.

After inserting a new lamp in the housing the process is reversed to return the device into the position shown in Figs. 1 and 2, whereby the electrical and cooling medium connections are automatically made. It should be noted that in this case the cooling liquid starts to circulate before the electrical contacts are made.

While we have described our invention in connection with specific examples and applications, we do not wish to be limited thereto but desire the appended claims to be construed as broadly as permissible in view of the prior art,

What we claim is:

1. A lighting device comprising a fixed head, a lamp housing movably mounted on said head, a liquid-cooled lamp disposed within said housing, and means mounted on said fixed head and said housing for energizing the lamp and for supplying a cooling liquid thereto only when the lamp housing occupies its operative position, said means comprising cooperating passageways in said head and in said housing, and cooperating electrical contacts.

2. A lighting device comprising a fixed head, a lamp housing movably mounted on said head, a liquid-cooled lamp within said housing, means for supplying energizing current and cooling liquid to said lamp, and means mounted upon said fixed head and housing for interrupting the supply of energizing current and cooling liquid when the lamp housing is moved from its operative position, said latter means comprising cooperating passageways in said head and housing and cooperating electrical contacts.

3. A lighting device comprising a fixed head, a member rotataby mounted on said head, a lamp housing slidably supported on said member, a liquid-cooled lamp disposed within a cavity of said housing, means including passageways in said head and in said member to supply a cooling liquid to said cavity when said member and lamp housing are rotated into a position corresponding to the operative position of said housing, and means for energizing said lamp when said housing occupies its operative position, said latter means comprising an electric contact device, said contact device comprising locking means for locking the lamp housing in its operative position.

4. A lighting device comprising a fixed head provided with a passageway for a cooling liquid, a lamp housing rotatably mounted on said head and provided with a cavity and an inlet and an outlet passageway for the supply and removal of cooling liquid thereto, said inlet passageway being connected to the passageway in the head only when the lamp housing is in its operative position, a lamp within said cavity, and means for supplying energizing current to said lamp only when the lamp housing is in its operative position, said means comprising electrical contacts supported by said housing and cooperating electrical contacts supported from said head.

CORNELIS BOL. ADRIANUS LINNEMANS. 

